On the other hand, let's say they aren't slaves. If they aren't slaves, in which case they were illegally acquired, weren't they? Forget mutiny, forget piracy, forget murder and all the rest. Those are subsequent irrelevant occurrences. Ignore everything but the pre-eminent issue at hand. The wrongful transfer of stolen goods. Either way, we win.
Sir, this war must be waged on the battlefield of righteousness.